The present invention relates to a locking swivel device for connection with a drill string and for conducting a drilling fluid to the drill string. Further, the present invention is directed at a locking swivel device which is actuatable between a disengaged condition, in which the swivel device is unlocked to permit rotation of the drill string, and an engaged condition, in which the swivel device is locked to inhibit rotation of the drill string in at least one direction, and preferably both. The swivel device is actuated to the engaged condition by a pressure exerted by the drilling fluid.
Often during drilling operations, a conventional drilling swivel or swivel mechanism is connected with the drill string at the surface such that the drill string extends from the swivel into the wellbore downhole. The drilling fluid for conducting the drilling operation is conducted from a surface fluid pump through a kelly hose to the swivel. The drilling fluid is then conducted through the swivel and into the attached drill string such that the drilling fluid is directed downhole for performance of the drilling operation.
In addition to conducting the drilling fluid to the drill string, the swivel also supports the drill string in the wellbore in a manner such that the drill string is rotatable within the wellbore. Conventional swivels typically permit rotation of the drill string in either direction within the wellbore. In other words, the drill string may be rotated in either a clockwise or a counterclockwise direction as desired. The ability to rotate the drill string within the wellbore may be desirable for a number of reasons. For instance, the ability to rotate the drill string will facilitate the connection or disconnection of the drill pipe sections comprising the drill string and will facilitate the orienting of the drill string within the wellbore to a desired orientation.
However, conventional swivels often permit the rotation of the drill string in both directions at all times during the drilling operation, including while the drilling fluid is being pumped through the swivel to the drill string. The ability to rotate at all times throughout the drilling operation may not be desirable in a number of applications.
For instance, it is desirable to be able to lock the swivel where the swivel is to be used in conjunction with a downhole positive displacement mud motor. Specifically, the downhole motor is connected with a downhole end of the drill string for drilling the wellbore. Although rotation of the drill string in both directions may be desirable for a number of reasons, including permitting the making up or breaking down of the drill string, rotation of the drill string tends not to be desirable during the actual drilling operation. For instance, when the downhole motor is being operated, the motor creates or generates an amount of reactive torque within the drill string attached thereto. In order to facilitate the drilling operation, it is desirable to hold or otherwise counteract this reactive torque by inhibiting the rotation of the drill string.
Further, it is desirable to be able to lock the swivel in other applications such as where the swivel is placed or located between a rotary top drive unit and the drill string. In this case, locking of the swivel permits rotational movement provided by the top drive unit to be transmitted through the swivel to the drill string. Conversely, unlocking of the swivel inhibits the transmission of the rotational movement. As a result, various operations such as wireline operations may be performed while allowing the drill string to freely rotate.
Thus, there is a need for the swivel to provide a locking mechanism such that the drill string may be selectively either permitted to rotate or inhibited from rotation within the wellbore as required for the particular task being performed. Although various locking swivels have been provided in response to this need, none appear to have provided a fully satisfactory result.
For instance, International Publication Number WO 98/29637 published Jul. 9, 1998 by Helms describes a locking swivel for use in drilling applications which allows the operator to selectively engage and disengage the swivel to permit or inhibit rotational movement of the attached drill string. The locking swivel is comprised of a locking mandrel movable within a lower body and a swivel mandrel. The locking mandrel has splines at each end for engaging splined surfaces provided in both the body and the swivel mandrel. The locking mandrel is movable either up or down and thereby into or out of engagement with the splined surface in the swivel mandrel and the splined surface in the lower body.
A hydraulic chamber is formed between an exterior wall of the locking mandrel and an interior wall of the lower body. A dynamic seal means mounted with the locking mandrel divides the chamber into two sealed portions. Further, two hydraulic fitting ports are provided in the lower body and are disposed on either side of the dynamic seal means. In other words, one hydraulic port communicates with each sealed portion of the hydraulic chamber. The hydraulic fitting ports are connected by standard hydraulic lines to a hydraulic pump.
The locking mandrel is actuated into and out of engagement with the splined surfaces through the use of the hydraulic pump and the two hydraulic fitting ports. If the operator desires to lock the swivel, the operator directs the flow of hydraulic fluid to the first hydraulic fitting port to move the locking mandrel upwards such that the splines of the locking mandrel are engaged with the splined surfaces of the lower body and the swivel mandrel. If the operator desires to unlock the swivel, the operator switches the flow of hydraulic fluid to the second hydraulic fitting port to move the locking mandrel downwards such that the splines of the locking mandrel are disengaged with the splined surfaces of the lower body and the swivel mandrel.
Thus, Helms provides a relatively complex structure for locking and unlocking the swivel which is actuated by and used in conjunction with a separate hydraulic system and hydraulic pump. Further, given the manner of actuating the swivel, Helms requires manual handling or intervention by an operator in order to lock and unlock the swivel. Manual handling or intervention by an operator may be undesirable in some circumstances.
In addition, Canadian Patent Number 2,237,309 issued Jun. 22, 1999 to Brown et. al. is directed at a method and an apparatus for controlling reactive torque on a drill string while drilling. Specifically, a tubular mandrel connected with the drill string is rotatably mounted to a housing. A ratchet mechanism is provided between the mandrel and the housing for controlling the rotation of the mandrel within the housing. The ratchet mechanism permits rotation of the mandrel freely in a clockwise direction and prevents rotation of the mandrel in a counterclockwise direction.
More particularly, the ratchet mechanism is comprised of a ring of sloped ratchet teeth fixed to an exterior surface of the mandrel. A plurality of pins extend through the housing to engage the ratchet teeth. Further, the pins are biased by a spring into an engaged position in which the pins are engaged with the teeth thereby permitting rotation in a clockwise direction and precluding rotation in a counterclockwise direction. Alternately, the pins may be manually retracted from the teeth to a disengaged position in which the mandrel may be rotated in either direction.
Thus, as in Helms Brown et. al. requires manual handling or intervention by an operator in order to unlock or disengage the apparatus, particularly given that the ratchet mechanism is biased to the engaged position. As indicated, manual handling or intervention by an operator may be undesirable in some circumstances.
As a result, there remains a need in the industry for a locking swivel device. In particular, there remains a need for a locking swivel device having a relatively uncomplicated structure. In addition, there remains a need for a swivel device which is actuated without the intervention or manual handling of an operator or other rig personnel.
The present invention relates to a locking swivel device for connection with a drill string and for conducting a drilling fluid to the drill string. Further, the present invention relates to a locking swivel device which is actuatable between a disengaged condition, in which the swivel device is unlocked to permit rotation of the drill string relative to the device, and an engaged condition, in which the swivel device is locked to inhibit rotation of the drill string relative to the device.
In the engaged condition, the swivel device may inhibit rotation of the drill string in either or both of a clockwise and a counterclockwise direction relative to the swivel device. In the preferred embodiment, the swivel device inhibits rotation of the drill string in both the clockwise and counterclockwise directions.
Preferably, the swivel device is actuated to the engaged condition by a pressure exerted by the drilling fluid. Further, the swivel device is preferably actuated without the intervention or manual handling of an operator or other rig personnel. In the preferred embodiment, the swivel device is locked or actuated to the engaged condition automatically while the drilling fluid is being conducted by the swivel device to the drill string.
The locking swivel device is provided for connection with a drill string. The swivel device may be connected with the drill string at any location along the length of the drill string between a distal end located or positioned downhole and a proximal end located or positioned uphole at the ground surface. However, the swivel device is preferably connected with the proximal end of the drill string in that the swivel device is connected, attached or affixed with the drill string at, adjacent or in proximity to the proximal end of the drill string such that the swivel device is accessible from the surface during drilling operations.
Further, the swivel device may be connected with a drill string intended for use for either or both rotary or non-rotary drilling. For instance, the swivel device may be connected with a drill string which rotates during the drilling operation for rotary drilling of the wellbore. In this case, a top drive unit may be connected with the swivel device. As a result, locking of the swivel device permits rotational movement provided by the top drive unit to be transmitted through the swivel device to the drill string such that the drill string is rotated within the wellbore. Conversely, unlocking of the swivel device inhibits the transmission of the rotational movement from the top drive unit to the drill string. Preferably, as indicated above, the swivel device is locked or actuated to the engaged condition by the pressure exerted by the drilling fluid being conducted to the drill string to perform the rotary drilling operation.
However, in the preferred embodiment, the swivel device is connected with a drill string which is not intended to rotate during the drilling operation for non-rotary or sliding drilling of the wellbore. In this case, the swivel device of the within invention is intended for use in conjunction with a downhole drilling motor. More particularly, a downhole positive displacement motor is connected with the distal end of the drill string for drilling the wellbore, while the swivel device is connected with the proximal end of the drill string. Again, as indicated above, the swivel device is preferably locked or actuated to the engaged condition by the pressure exerted by the drilling fluid during actuation of the downhole motor by the drilling fluid to perform the drilling operation.
As a result, in the preferred embodiment, the swivel device holds or counteracts the reactive torque created by the downhole motor in the engaged condition while the drilling operation is being performed. Conversely, when the drilling operation is not being performed and drilling fluid is not being conducted through the swivel device and the drill string, the drill string may be rotated relative to the swivel device which permits the making and breaking of threaded drill string connections.
As stated, the swivel device is preferably supported at the surface above the wellbore such that the drill string is supported within the wellbore by the swivel device. The swivel device may be supported at the surface by any mechanism, structure, device or method compatible with the specific drilling operation to be performed. However, preferably, the swivel device is supported at the surface by the drilling rig, and more preferably, by the elevators of the drilling rig.
Further, the drilling fluid may be comprised of any fluid, being a liquid, gas or a mixture thereof, suitable for performing the specific drilling operation. As indicated, the swivel device is preferably used in conjunction with a downhole drilling motor. Thus, the drilling fluid is preferably comprised of a fluid suitable for and capable of operating the downhole motor, such as mud, water, air or a combination thereof.
In a first aspect of the invention, the invention is comprised of a locking swivel device for connection with a proximal end of a drill string and for conducting a drilling fluid to the drill string. The locking swivel device is comprised of:
(a) a housing;
(b) a mandrel rotatably supported within the housing such that an annular space is defined between the housing and the mandrel, wherein one of the housing and the mandrel is connectable with the drill string such that the drill string rotates therewith; and
(c) a clutch assembly within the annular space and actuatable between an engaged condition in which the clutch assembly engages the housing and the mandrel in order to inhibit the rotation of the mandrel relative to the housing and a disengaged condition in which the clutch assembly disengages the housing and the mandrel in order to permit the rotation of the mandrel relative to the housing, wherein the clutch assembly is actuated to the engaged condition by a pressure exerted by the drilling fluid.
Further, the clutch assembly is biased towards the disengaged condition. Thus, when the pressure is not being exerted by the drilling fluid, the clutch assembly is actuated to the disengaged condition. Thus, when the swivel device is at rest and the pressure is not being exerted by the drilling fluid, the clutch assembly is in the disengaged condition. Upon the application of the pressure of the drilling fluid, the clutch assembly is actuated to the engaged condition. Finally, upon a release of that pressure, the clutch assembly is urged to return to the disengaged condition.
Thus, the clutch assembly is actuated between the engaged and disengaged conditions by the exertion or lack of exertion of the pressure of the drilling fluid. More particularly, the clutch assembly is designed and configured to be actuated to the engaged condition by the exertion of a predetermined actuation pressure of the drilling fluid. In other words, if the drilling fluid exerts a pressure which i; greater than or equal to the predetermined actuation pressure, the clutch assembly will be actuated to the engaged condition. However, the clutch assembly will be actuated to the disengaged condition when the pressure of the drilling fluid is less than the predetermined actuation pressure.
As indicated, the mandrel is rotatably supported within the housing to permit the rotation of the mandrel relative to the housing. Further, one of the housing and the mandrel is connectable with the drill string such that the drill string rotates therewith. Thru, for instance, the housing may be connectable with the drill string such that rotation of the housing rotates the drill string. In this case, the housing and attached drill string rotate relative to the mandrel. However, preferably, the mandrel is connectable with the drill string such that rotation of the mandrel rotates the drill string. In this case, the mandrel and attached drill string rotate relative to the housing.
In the preferred embodiment, the swivel device is used in conjunction with a downhole motor. Thus, the drill string is preferably inhibited from rotating within the wellbore during the operation of the downhole motor or during drilling of the wellbore. As a result, in the preferred embodiment in which the mandrel is connectable with the drill string, the swivel device is further comprised of an anti-rotation device associated with the housing for inhibiting the rotation of the housing such that the housing is substantially stationary in order that the mandrel is rotatable within the stationary housing when the clutch assembly is disengaged and the mandrel and the housing are substantially stationary or inhibited from rotation when the clutch assembly is engaged. As a result, the drill string connected with the mandrel is rotatable within the wellbore when the clutch assembly is disengaged and the drill string is inhibited from rotation within the wellbore when the clutch assembly is engaged.
Further, the swivel device includes a fluid path for conducting the drilling fluid through the swivel device to the drill string. One or more of the housing, the mandrel or the annular space defined therebetween may define all or a portion of the fluid path for conducting the drilling fluid to the drill string.
Preferably, the mandrel defines a bore which communicates with the drill string in order that the drilling fluid may be conducted through the mandrel to the drill string. In the preferred embodiment, the mandrel has a distal end for connection with the drill string and an opposing proximal end. The bore of the mandrel may extend longitudinally within the mandrel between the proximal and distal ends or for any portion or section thereof. However, preferably, the bore at least extends to the distal end of the mandrel such that the bore of the mandrel communicates with a bore of the drill string at the distal end of the mandrel. In the preferred embodiment, the bore of the mandrel extends between the proximal and distal ends of the mandrel such that the drilling fluid enters the proximal end of the mandrel and is conducted through the mandrel to the distal end.
Further, the housing is preferably comprised of an inlet for conducting the drilling fluid therein, wherein the inlet communicates with the bore of the mandrel and wherein the pressure of the drilling fluid is communicated to the annular space to actuate the clutch assembly. Once the drilling fluid is conducted into the housing by the inlet, the drilling fluid may be conducted or communicated from the inlet to the bore of the mandrel in any manner and by any structure or element comprising the swivel device. Further, the drilling fluid conducted into the housing may enter into or communicate with the bore of the mandrel at any location or position along the length of the bore of the mandrel. However, in the preferred embodiment, the drilling fluid enters into or communicates with the bore of the mandrel at the proximal end of the mandrel.
As stated, the pressure of the drilling fluid is communicated to the annular space to actuate the clutch assembly. The pressure may be directly communicated to the annular space by exposing the annular space to the drilling fluid or the pressure may be indirectly communicated to the annular space by any mechanism or structure capable of transmitting or communicating the pressure from the fluid to the annular space. For instance, a fluid filled chamber may be located between the drilling fluid and the annular space for communicating the pressure of the drilling fluid therethrough.
Preferably, the housing defines a fluid chamber associated with the inlet, wherein the pressure of the drilling fluid within the fluid chamber is communicated to the annular space to actuate the clutch assembly. Again, the pressure may be communicated directly or indirectly. Further, the fluid chamber may be separate or distinct from the fluid path provided for conducting the drilling fluid to the drill string. For instance, a major portion of the drilling fluid may be conducted by the fluid path to the drill string for performance of the drilling operation, while a minor or lesser portion of the drilling fluid is conducted into the fluid chamber such that the pressure of the drilling fluid within the fluid chamber may communicate with the annular space to actuate the clutch assembly.
However, preferably, the fluid chamber forms a part or portion of the fluid path. In the preferred embodiment, the fluid chamber conducts the drilling fluid from the inlet to the bore of the mandrel. Thus, the fluid path of the drilling fluid is comprised of the fluid chamber and the bore of the mandrel such that the drilling fluid is conducted through the inlet into the fluid chamber, from the fluid chamber to the bore of the mandrel and from the bore of the mandrel to the drill string. While the drilling fluid is being conducted through the fluid chamber, the pressure of the drilling fluid within the fluid chamber is communicated to the annular space to actuate the clutch assembly.
The clutch assembly may be comprised of any mechanism, device or structure actuatable between the engaged and disengaged conditions described herein and which may be actuated to the engaged condition by the pressure exerted by the drilling fluid. Further, the clutch assembly may inhibit rotation of the mandrel relative to the housing in either or both of a clockwise and a counterclockwise direction in the engaged condition. For instance, the clutch assembly may inhibit rotation of the mandrel relative to the housing in only one direction in the engaged condition. In this case, the clutch assembly may be comprised of any free-wheeling clutch assembly. However, in the preferred embodiment, the clutch assembly inhibits rotation of the mandrel relative to the housing in both the clockwise and counterclockwise directions.
In the preferred embodiment, the clutch assembly is comprised of a stationary member associated with one of the housing and the mandrel and a dynamic member associated with the other of the housing and the mandrel, wherein the dynamic member is movable within the annular space towards the stationary member for engagement therewith to actuate the clutch assembly to the engaged condition and away from the stationary member for disengagement therefrom to actuate the clutch assembly to the disengaged condition.
As indicated, the stationary member is associated with one of the housing and the mandrel and the dynamic member is associated with the other of the housing and the mandrel. The stationary and dynamic members may be associated with the housing and the mandrel in any manner and by any mechanism or structure permitting the operation of the clutch assembly as described herein. For instance, each of the stationary member and the dynamic member may be connected, mounted, fastened or otherwise affixed with the housing or the mandrel. However, preferably, the stationary member is fixedly mounted with one of the housing and the mandrel and the dynamic member is movably mounted with the other of the housing and the mandrel.
In the preferred embodiment, the stationary member is fixedly mounted with the mandrel and the dynamic member is movably mounted with the housing. Further, in the preferred embodiment, the stationary member defines a bore for receiving the mandrel therein such that the stationary member is mounted about an outer surface of the mandrel. In addition, the dynamic member defines a bore for receiving the mandrel therein such that the dynamic member is positioned about the outer surface of the mandrel and mounted with an inner surface of the housing.
Further, in the preferred embodiment, the pressure of the drilling fluid is communicated to the dynamic member within the annular space such that the pressure exerted by the drilling fluid moves the dynamic member towards the stationary member for engagement therewith. In addition, the dynamic member is preferably biased away from the stationary member such that the dynamic member is moved away from the stationary member for disengagement therefrom when the pressure is not being exerted by the drilling fluid.
In the preferred embodiment, the clutch assembly is further comprised of a biasing device associated with the dynamic member for urging the dynamic member away from the stationary member for disengagement therefrom. The biasing device may be comprised of any device, mechanism or structure capable of urging the dynamic member away from the stationary member. However, in the preferred embodiment, the biasing device is comprised of at least one spring and wherein the spring has a spring force sufficient to urge the dynamic member away from the stationary member to the disengaged condition when the pressure is not being exerted by the drilling fluid.
The stationary member has an engagement surface and the dynamic member has a corresponding engagement surface, wherein the engagement surface of the stationary member is engaged with the engagement surface of the dynamic member in the engaged condition of the clutch assembly such that rotation of the mandrel relative to the housing is inhibited and wherein the engagement surface of the stationary member is disengaged from the engagement surface of the dynamic member in the disengaged condition of the clutch assembly such that rotation of the mandrel relative to the housing is permitted.
The engagement surface of the stationary member and the corresponding engagement surface of the dynamic member may have any shape or configuration able to inhibit, and preferably prevent, the rotation of the mandrel relative to the housing when engaged. However, preferably, the engagement surface of the stationary member defines a plurality of stationary teeth and the engagement surface of the dynamic member defines a plurality of corresponding dynamic teeth compatible with the stationary teeth for engagement therewith.
In addition, the swivel device is preferably comprised of a bearing assembly within the annular space for axially and radially supporting the mandrel within the housing such that the mandrel is rotatable therein. The bearing assembly may be comprised of any device or mechanism capable of axially and radially supporting the mandrel within the housing, such as one or more bearings, bushings or a combination thereof.
In the preferred embodiment, the bearing assembly is comprised of at least one tapered bearing. Preferably the tapered bearing provides both axial and radial support to the mandrel. The tapered bearing may be positioned or mounted within the swivel device in any manner. However, preferably, the mandrel defines a downwardly facing bearing shoulder, the housing defines an upwardly facing bearing shoulder and the tapered bearing is positioned therebetween such that the mandrel is rotatably supported by the housing.
In addition, the tapered bearing is preferably preloaded within the swivel device. Although the tapered bearing may be preloaded in any manner and by any mechanism, structure or device capable of preloading the tapered bearing by a desired preloading force, the tapered bearing is preferably preloaded by the spring force of the spring comprising the biasing device.
Further, in the preferred embodiment, the bearing assembly may be further comprised of at least one radial bearing.
Finally, the swivel device is preferably further comprised of a sealing assembly for sealing the annular space in order to inhibit the entry of the drilling fluid therein. In the preferred embodiment, one or more seals are provided between the dynamic member and the adjacent inner surface of the housing and outer surface of the mandrel such that drilling fluid is inhibited from passing from the fluid chamber into the annular space.